Copernicus Meteorological Drought Tracking (ERA5)

This version of the Combined Drought Indicator (CDI) utilizes ERA5 reanalysis data as the primary input for the precipitation component (SPI), rather than gauge-only or other satellite-blended products. ERA5, produced by ECMWF, offers comprehensive spatial coverage and temporal consistency, making it valuable for regions where gauge networks are failing or sparse. Like the standard CDI, this dataset synthesizes rainfall deficits (via ERA5), soil moisture anomalies, and vegetation stress into a single classification system to monitor the evolution of drought episodes.

The Standardized Precipitation Index (SPI) is the globally recommended standard for characterizing meteorological drought. It quantifies observed precipitation as a standardized deviation from the long-term probability distribution function for a specific location and time scale. This dataset typically includes multiple time-scales (e.g., 1-month, 3-month, 6-month, 12-month) to capture different types of drought impacts, from immediate soil moisture deficits to long-term hydrological stress. Because SPI is normalized, it allows for safe comparisons between different climatic zones—allowing a wet region and a dry region to be compared on the same scale of drought severity.

The Combined Drought Indicator (CDI) dataset identifies different drought classes and their extent, focusing on vegetated areas (at risk, affected, and recovering). It integrates three complementary indicators — Standardized Precipitation Index (SPI), Soil Moisture Index Anomaly (SMA), and FAPAR anomaly — to capture meteorological, agricultural, and vegetation drought conditions. The dataset consists of raster maps with a spatial resolution of ~5 km at the Equator, using WGS84 (EPSG:4326) as the coordinate system. Data are available from 2012 to the present, updated every 10 days, which is suitable for monitoring short-term crop stress. Produced operationally by the European Drought Observatory (EDO), the CDI maps are freely accessible online. Recent updates include: CDIv3 (March 2023): integration of static crop masks to limit analysis to active growing seasons. CDIv4 (June 2024): introduction of dynamic snow masks and a new soil moisture input based on EFAS v5. More: https://drought.emergency.copernicus.eu/data/factsheets/factsheet_combinedDroughtIndicator_v4.pdf

Drought: areas where the change in the Standardized Precipitation Index (SPI) is below -20%. Pixels with a value lower than the specified threshold (-20%) were given a value of 1 (YES response) The long-term change in annual drought is calculated over a 20 year time period, from 2021 to 2040 (near term), with SSP5-8.5. **Data publication:** 2022-01-26 **Contact points:** Resource Contact: [IPCC WGI Interactive Atlas](mailto:ipcc-ddc@ifca.unican.es) Metadata Contact: [OCB Environment](mailto:OCB-Environment-List@fao.org) **Resource constraints:** More information on IPCC data license at: https://interactive-atlas.ipcc.ch/license **Online resources:**

The Combined Drought Indicator (CDI) dataset developed at ACMAD is designed as an operational drought-monitoring product that synthesizes multiple biophysical signals into a single, coherent assessment of drought conditions across Africa. Rather than relying on a single indicator, the ACMAD CDI combines information from rainfall-based drought indices and satellite-derived vegetation condition metrics, applying rule-based logic to identify areas where these independent indicators consistently point to drought stress. This convergence approach reduces the risk of false alarms that can arise from short-term rainfall variability or vegetation anomalies unrelated to drought. The data exist in two forms one based on GPCC while another based on Era5 precipitation. The dataset is particularly useful in the African context, where ground observations are sparse and climatic gradients are strong across regions. By using harmonized, gridded datasets, the CDI provides a comparable drought signal across national boundaries, supporting regional coordination and continental-scale analysis. Its categorical outputs are intentionally simple and policy-ready, making them suitable for drought bulletins, early-warning communications, and high-level decision support. Importantly, the CDI is not intended to replace detailed drought diagnostics or impact assessments. Instead, it serves as a convergence and confirmation tool that highlights areas requiring closer analysis and expert interpretation. In this role, the CDI acts as a bridge between complex climate data and practical drought-risk management, enabling timely, consistent, and defensible drought monitoring at regional and continental scales.

Standardized Precipitation Index (SPI) for Mozambiqueshowing rainfall anomalies relative to historical averages. Negative values indicate drought conditions, positive values indicate above-normal rainfall. Use this layer for drought early warning, food security analysis, and climate monitoring.